In known conductor line systems, a movable electrical load travels along a conductor line. To supply the load with electric energy, it is equipped with a current collector whose conductor contacts engage in conductor strands guided along the conductor line. The load, for example, can be lifting gear of an overhead track conveyor, a cable trolley movable on rails or also so-called E-RTG container cranes, which are equipped with an electric drive supplied with electrical power from the conductor line.
In order to be able to transmit data, for example, control data, to and from loads, slotted waveguides, guided parallel to the conductor strands of the conductor line, are used in known conductor line systems, in which antennas arranged on the load engage. DE 10 2014 107 466 A1 discloses such a conductor line system.
In some circumstances, the electrical processes occurring in the power-transmitting conductor strands have an adverse effect on RF transmission in the slotted waveguide. For example, if the sliding contacts of the current collector are briefly raised from the sliding contact surfaces of the conductor line, brief interruptions of direct current flow can occur and spark gaps are formed that can briefly generate pulses containing high-frequency components. Since the slotted waveguide and the grounding conductor strand form a common unit there, data transmission during bleeding off of current via the grounding conductor strand can also adversely affect data transmission.
Another problem in such conductor line systems with slotted waveguides for data transmission is that they are often used in areas with dirty and damp environments, for example, in container handling facilities in harbors.
DE 10 2011 119 351 A1 discloses a conductor line in which current-conducting conductor strands facing laterally outward are arranged with their openings on a double-T support. A slotted waveguide is also arranged there, whose longitudinal slot faces laterally outward; thus, dirt and especially rainwater can penetrate relatively easily into the longitudinal slot from the side and deposit especially on the lower horizontal slot surface.
The longitudinal slot in the slotted waveguide disclosed in DE 10 2012 002 085 A1 also faces to the side. To avoid penetration of rainwater into the longitudinal slot obliquely from the top, a deflection part bent twice by 45° is provided there on the upper wall of the longitudinal slot, so that the opening of the longitudinal slot is directed vertically downward after the deflection part. The antenna of the rail vehicle then engages vertically into the longitudinal slot from below, so that the electromagnetic waves must be deflected from the T-shaped cavity profile of the slotted waveguide downward to the longitudinal slot by means of the deflection part. This is a drawback for data transmission owing to the asymmetry of the angled longitudinal slot and the longer transmission path of the waves in contrast to a straight longitudinal slot.
Penetration of rainwater is avoided in the conductor line system of DE 10 2004 008 571 A1 with support rails designed as double-T supports with conductor strands arranged laterally on them, so that the slotted waveguide is arranged in the foot part of the double-T support and the longitudinal slot of the slotted waveguide discharges vertically downward. Dirt adhering to the antenna and dirt swirled up from below, as is the case especially in the area of E-RTG container cranes, however, penetrates unhindered through the longitudinal slot into the slotted waveguide. Since such E-RTG container cranes are preferably used in harbors with humid, saline air, the rising moisture also penetrates unhindered into the slotted waveguide and leads to rapid corrosion there of both the slotted waveguide and the movable antennas that can be introduced into the slotted waveguide.
EP 1 724 952 A1 concerns a communication system that provides high-speed and high-quality communication in an elongated communications area and implements leaky optical fibers. The optical fiber is then of the GI type with a core that is structured so that the refractive index is high at the center, diminishes gradually as it approaches the periphery and can have scatterers mixed therein. When modulated light from a transmitter enters the optical fiber, the modulated light passes through the optical fiber, whereas part of the light emerges from the side. A receiver receives this leakage light and demodulates it in order to obtain data.
DE 10 2004 020 324 A1 discloses an optical method and an optical device for monitoring of an electrical conductor, in which an optical sensor is arranged on or in a component of the conductor and a light signal fed into the optical sensor is changed based on a physical quantity at the location of the optical sensor. A measured value for the physical quantity is determined from the deformation-related change of the light signal.
EP 2 056 492 A1 discloses a mobile optical communication system comprising a railway and a train. Several leaky optical fibers, a number of optical fibers and a number of light receivers are arranged along the rail path. The leaky optical fiber contains transparent parts. The nontransparent parts are arranged discontinuously along the longitudinal direction and are arranged at intervals that are smaller or equal to a length of the train with reference to a travel direction of the train. Several light receivers arranged on the train are arranged along the entire length of the train in the travel direction in intervals smaller than or equal to a fixed length. Two adjacent light transmitters that are arranged on the train are arranged so that optical images from two light transmitters adjacent to the optical fiber have an overlapping area with reference to the travel direction.
A shortcoming in the conductor line systems just described, among other things, is the sensitivity of the known contactless radio data transmission relative to electrical incidents on the power-transmitting conductor lines, disturbances from other radio connections and the sensitivity relative to a corrosive environment.